How to Trade Biotech PDUFA Dates: A Complete Playbook

Every biotech trader eventually learns the same lesson the expensive way: PDUFA dates are the most predictable catalysts in the market, and also the easiest to trade badly. You know the date weeks in advance. You know the decision is binary. And you still lose money, because knowing when the event happens is not the same as knowing what is priced in.

This playbook covers the full lifecycle of a PDUFA trade — finding the date, evaluating the setup, sizing the position, and exiting — using real examples from the 2026 calendar. Our FDA calendar tracks every confirmed date across the sector; this is the framework for using it.

Step 1: Start from the calendar, not the headline

The trade begins when the FDA accepts the filing, not when the decision approaches. Acceptance comes with the review type (Priority = 6-month clock, Standard = 10-month) and the target action date. BioPharmCatalyst and the companies’ own press releases are the primary sources; we consolidate confirmed dates on the FDA calendar and in month-ahead pieces like our September 2026 PDUFA calendar.

The reason to start early: the best PDUFA entries are 4 to 8 weeks before the date, after the AdCom (if any) has resolved but before the pre-decision run-up crowds in. Buying the week of the decision means paying the maximum price for the maximum uncertainty.

Step 2: Score the approval probability

Five factors, in rough order of predictive power:

1. Clinical trial quality. Did the pivotal trial meet its primary endpoint with a clean p-value and a placebo-adjusted gap that is hard to argue with? Protagonist’s rusfertide VERIFY data — 76.9% versus 32.9% response, p<0.0001 — is the 2026 gold standard; the base rate on that filing is well north of 90%. Compare EyePoint’s LUGANO miss, where a failed primary endpoint rescued by a post-hoc exclusion was never going to clear the bar (see our DURAVYU analysis).

2. Regulatory signals. Breakthrough Therapy designation, Fast Track, Priority Review, and a completed pre-NDA meeting all raise the probability. A prior CRL on the same filing lowers it — Ultragenyx’s UX111 BLA resubmission (PDUFA September 19, 2026) carries the resubmission discount even though the biomarker data is strong.

3. AdCom outcome, if there was one. The FDA follows the advisory committee vote the large majority of the time. Replimune’s RP1 panel voted 10-1 (with one abstention recorded as a no in some counts) in July 2026 and the drug was approved on August 3. A negative vote is close to a death sentence for the filing — and a trading gift for anyone positioned short into the meeting, since AdCom votes are public, scheduled, and tradeable before the PDUFA date. Our AdCom explainer covers the mechanics.

4. Surrogate endpoint risk. Accelerated approvals based on biomarkers (CSF heparan sulfate, MRD negativity, cornstarch reduction) have a higher CRL rate than trials on survival or symptom endpoints, especially when the patient population is small. That does not make them bad trades — it changes the position size. See our accelerated approval explainer.

5. Competitive and political context. The FDA of any given year has risk tolerance that shifts. Drugs in crowded classes with marginal differentiation face sharper scrutiny than first-in-class therapies for untreated diseases.

Step 3: The two trades, and when to choose each

The run-up trade. Buy 4 to 8 weeks out, sell into strength the week before the date. This works because pre-PDUFA drift is one of the most consistent patterns in biotech: funds build positions into known catalysts. The cost: you exit before the binary resolves, so you capture 60-70% of a positive move while avoiding the crash risk. This is the right trade when the approval is largely priced and downside is asymmetric — our rusfertide final-hours analysis is the live example: at $10 billion market cap with approval at 90%, the reward for holding through the print is a drift and the risk is a 50% drawdown.

The binary trade. Hold through the decision. This is only correct when the market is pricing meaningful doubt — either a genuine CRL probability or an under-owned setup where approval would force repricing. Praxis’s relutrigine (September 27, 2026) fits: a small-cap with a Priority Review orphan filing where approval transforms the commercial story. Size for the worst case, not the base case.

Step 4: Position sizing for binary outcomes

The rule: never let a single PDUFA outcome cost more than 2-3% of your portfolio. If the stock can halve on a CRL (it can — Replimune traded at a fraction of its pre-AdCom level during its earlier rejections, and EyePoint lost 63% in one session on a missed endpoint), a position you can’t afford to watch drop 50% is a position that’s too big. Work backwards: 2% maximum loss ÷ 50% drawdown = 4% maximum position size. For 90%-probability setups you can stretch this; for coin-flip binaries, cut it in half again.

Options are the alternative sizing tool — a defined-risk call position caps the loss at the premium while preserving most of the binary upside. For the mechanics, see trading biotech options on FDA catalysts.

Step 5: Exits, on every outcome

Approval: Sell the pop or fade it — historically roughly half the post-approval pops retrace within weeks as the “sell the news” flow hits. The exception is when approval unlocks a new narrative (first-in-class label, unexpected breadth). Moderna’s post-Phase-3 melt-up in August 2026 kept running because the win validated a platform, not a single drug. Most approvals are not that.

CRL: Do not average down. A CRL changes the asset’s timeline by 6-18 months and sometimes the thesis itself. Exit or re-underwrite from scratch.

Delay/extension: PDUFA dates slip — Biogen’s LEQEMBI IQLIK sBLA was extended by three months in 2026 via a major amendment before early approval. An extension is information: it means the FDA asked for something. Treat it as a partial resolution of the uncertainty, usually mildly negative.

Early approval: The best outcome and the most dangerous to hold. Take the gain.

The five mistakes that cost the most money

1. Buying the pop after the headline. The move happened. You are someone else’s exit liquidity.
2. Confusing approval probability with trade attractiveness. A 95% approval at a price that already reflects 95% is a coin flip with extra steps.
3. Ignoring the label. Approvals come with labels, and narrow labels tank stocks that expected broad ones. Watch indication scope, safety language, and any post-marketing requirements.
4. Holding a binary through the print at full size. Whatever your conviction, the FDA is the counterparty.
5. Trading one date in isolation. The calendar clusters — September 2026 has 11 dates — and attention splits. The under-owned name in a crowded week often offers the better entry than the headline trade.

Where to go from here

• The live FDA calendar — every confirmed PDUFA date, updated as decisions land
• What is a PDUFA date? — the beginner’s foundation
• How to trade FDA catalysts — the run-up/binary/exit framework in detail
• September 2026 PDUFA calendar — this month’s slate ranked by materiality
• Trading biotech after FDA decisions — what happens in the hours after the headline

PDUFA trading rewards preparation over prediction. You will never know the FDA’s answer in advance. You can always know the date, the data, the base rates, and your own exit — before you enter.